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Discussion Starter · #1 ·
Do you guys know why do I get voltage read on 76 volt on a black wire at REC#1 &2 and at the box when breaker for for that line (black) is OFF but for Red is ON. Nothing is connected to the outlets. All other breakers in the panel are off.
Voltage reads at panel are following:

Phase A Phase B Multimeter Multimeter
Red Breaker Status: Black breaker Status: Lead 1 ON: Lead 2 ON: Voltage read:
1. ON ON Red Breaker Black Breaker 248.9
2. OFF OFF Red Breaker Black Breaker 0.868
3. OFF ON Red Breaker Black Breaker 77.4
4. OFF ON Red Breaker Neutral 44.4
5. ON OFF Red Breaker Black Breaker 44.2
6. ON OFF Neutral Black Breaker 76
6. OFF OFF Neutral Black Breaker 0.314
7. OFF OFF Red Breaker Neutral 0.622

Measurments were taken when Junction box was rewired as shown on Capture2 drawing. (Yes the black wire was left alone and wold still show voltage). FYI: there might be some other splices that are not visible to me behind drywall but this is what is visible and as I sad all other breakers are off in the panel . What could be the issue?
 

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Reading number 1 is correct.
The other readings may be phantom readings.
Plug a lamp into each receptacle and repeat the same test, and you should get close to zero.
 

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Discussion Starter · #3 ·
Am I understanding you correctly that 76 volts on a black conductor that is not connected to anything in the junction box and nothing other than the braker that is even removed from a panel is phantom reading ? Shouldnt that reading be closer to 0?
 

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That can definitely be a phantom reading. Adding a load as suggested will verify that assumption as Phantom voltage can deliver extremely little power, essentially zero.

Bud
 

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It should not be possible to turn off just one of the breakers. On a multi wire circuit the breakers should be tied so they both go off. Ideally it should be a double pole breaker.
 

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The old multiwire branch circuit did not have ties so what you are reading is, what I call, induced voltage from the other conductor. If you tried to turn on a light bulb or anything you will see that it doesn't work that is because it isn't true voltage.

If you took a non voltage tester, some call it a beeper that makes a sound when you place it near a hot wire, you would probably hear it beep even though there is no voltage present. It lies so close to another conductor that is hot and that is how the voltage is induced. I have seen it with 2 pieces of NM cable run atop of one another where one is hot and the other is off and you will still get a beep on the cable where it is not laying on top of the other.

I call it magic.
 

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Discussion Starter · #7 ·
That can definitely be a phantom reading. Adding a load as suggested will verify that assumption as Phantom voltage can deliver extremely little power, essentially zero.

Bud
Isn't 70 volt heck a lot to be phantom reading? Forgive me but I am trying to understand what do you mean by saying that Phantom voltage can deliver extremely little power? Ihad this thing plugged in previously as a test and light LED night light was still on but slightly dimmer while black wire breaker was off with red one on :
Light Product Automotive lighting Font Audio equipment
 

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Discussion Starter · #8 ·
The old multiwire branch circuit did not have ties so what you are reading is, what I call, induced voltage from the other conductor. If you tried to turn on a light bulb or anything you will see that it doesn't work that is because it isn't true voltage.

If you took a non voltage tester, some call it a beeper that makes a sound when you place it near a hot wire, you would probably hear it beep even though there is no voltage present. It lies so close to another conductor that is hot and that is how the voltage is induced. I have seen it with 2 pieces of NM cable run atop of one another where one is hot and the other is off and you will still get a beep on the cable where it is not laying on top of the other.

I call it magic.
Kinda makes sense but 70 volt read with Multimeter is kinda scarry and yes the beeping thing beeps as if it is HOT. Also this is a new circut -2018 looks like. I also posted reply above where this little Victor light was plugged in and was still showing light althogh dimmer. Next I will try plugging the lamp or something with more draw.
 

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The voltage reading is dependent upon several factors but it is REAL voltage. Static electricity can be as high as 25,000 volts but just scares those who get jolted. More typically about 10.000 volts.

But the input impedance of your meter plus the degree of coupling between wires is what gives you the reading.

Bud
 

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Discussion Starter · #10 ·
It should not be possible to turn off just one of the breakers. On a multi wire circuit the breakers should be tied so they both go off. Ideally it should be a double pole breaker.
Do they sell 2 tandem breakers with a tie between them? Need to get that one then, but still freaking out about that 70v read
 

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Discussion Starter · #11 ·
The voltage reading is dependent upon several factors but it is REAL voltage. Static electricity can be as high as 25,000 volts but just scares those who get jolted. More typically about 10.000 volts.

But the input impedance of your meter plus the degree of coupling between wires is what gives you the reading.

Bud
Understood. So based on my tests can we assume that I don't have some hackery happenign behind walls that may render these results ?
 

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Do you guys know why do I get voltage read on 76 volt on a black wire at REC#1 &2 and at the box when breaker for for that line (black) is OFF but for Red is ON. Nothing is connected to the outlets. All other breakers in the panel are off.
Voltage reads at panel are following:

Phase A Phase B Multimeter Multimeter
Red Breaker Status: Black breaker Status: Lead 1 ON: Lead 2 ON: Voltage read:
1. ON ON Red Breaker Black Breaker 248.9
2. OFF OFF Red Breaker Black Breaker 0.868
3. OFF ON Red Breaker Black Breaker 77.4
4. OFF ON Red Breaker Neutral 44.4
5. ON OFF Red Breaker Black Breaker 44.2
6. ON OFF Neutral Black Breaker 76
6. OFF OFF Neutral Black Breaker 0.314
7. OFF OFF Red Breaker Neutral 0.622

Measurments were taken when Junction box was rewired as shown on Capture2 drawing. (Yes the black wire was left alone and wold still show voltage). FYI: there might be some other splices that are not visible to me behind drywall but this is what is visible and as I sad all other breakers are off in the panel . What could be the issue?
Do you guys know why do I get voltage read on 76 volt on a black wire at REC#1 &2 and at the box when breaker for for that line (black) is OFF but for Red is ON. Nothing is connected to the outlets. All other breakers in the panel are off.
Voltage reads at panel are following:

Phase A Phase B Multimeter Multimeter
Red Breaker Status: Black breaker Status: Lead 1 ON: Lead 2 ON: Voltage read:
1. ON ON Red Breaker Black Breaker 248.9
2. OFF OFF Red Breaker Black Breaker 0.868
3. OFF ON Red Breaker Black Breaker 77.4
4. OFF ON Red Breaker Neutral 44.4
5. ON OFF Red Breaker Black Breaker 44.2
6. ON OFF Neutral Black Breaker 76
6. OFF OFF Neutral Black Breaker 0.314
7. OFF OFF Red Breaker Neutral 0.622

Measurments were taken when Junction box was rewired as shown on Capture2 drawing. (Yes the black wire was left alone and wold still show voltage). FYI: there might be some other splices that are not visible to me behind drywall but this is what is visible and as I sad all other breakers are off in the panel . What could be the issue?
You have a loose neutral. Those 2 circuits are sharing a neutral somewhere and it’s loose. That’s why you have voltage when it’s off. It’s not “phantom” it’s very real. Start trouble shooting.
 

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Discussion Starter · #17 ·
You have a loose neutral. Those 2 circuits are sharing a neutral somewhere and it’s loose. That’s why you have voltage when it’s off. It’s not “phantom” it’s very real. Start trouble shooting.
What do you mean by loose neutral? Yes as you can see per the drawing they do share a neutral. What do you mean it is loose somewhere? How would I beging to troubleshoot if I can't access the walls?
 

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What do you mean by loose neutral? Yes as you can see per the drawing they do share a neutral. What do you mean it is loose somewhere?
Yes, it’s loose somewhere in those circuits. In a receptacle, light switch, light fixtures etc. turn off both circuits to isolate what is on them, then start opening boxes and inspecting the neutral connections.
 

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Discussion Starter · #20 ·
Yes, it’s loose somewhere in those circuits. In a receptacle, light switch, light fixtures etc. turn off both circuits to isolate what is on them, then start opening boxes and inspecting the neutral connections.
There are only 3 outlets that I can see on those circuits and all connections are done well. and the main wire looks like coming into the junction box and branches to outlets from there. If there is nothing connected to the outlets even if the white wire loose on them,
this shouldn't produce the effects I am having. Am I wrong? I am trying to understand how loose neutral can create the voltage in the black wire that is not connected to anything other than the breaker that is off?
 
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